In this paper, a three-layered cement-based wave-absorbing board is designed and prepared by mixing wave-absorbing fillers such as nano-Si₃N₄, multi-layer nano graphene platelets (NGPs), nano-Ni, carbon fiber (CF) and carbon black (CB) into cement slurry. The effect of the amount of wave-absorbing fillers on the mechanical properties, resistivity and wave-absorbing reflectivity of cement slurry is studies. The microstructure of NGPs, nano-Si₃N₄ and the wave-absorbing board are characterized by TEM and SEM. Research shows that low content of NGPs and other wave-absorbing fillers can significantly reduce the resistivity of cement slurry and improve its mechanical strength, and dense massive crystals are precipitated in the cement hydration products. The reflectivity test reveals that in the frequency range of 2~18 GHz, the minimum reflectivity of the three-layered cement-based wave absorbing board reaches −18.8 dB, and the maximum bandwidth less than −10 dB reaches 15.3 GHz. This study can serve as reference for the preparation of new three-layered cement-based wave absorbing boards.

中文翻译：

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三层水泥基吸收板的机械电磁性能和微观结构研究

通过混合纳米Si ₃ N ₄，多层纳米石墨烯薄片（NGPs），纳米镍，碳纤维等吸波填料，设计并制备了三层水泥基吸波板。（CF）和炭黑（CB）制成水泥浆。研究了吸波填料的添加量对水泥浆力学性能，电阻率和吸波反射率的影响。NGP的微观结构，纳米Si ₃ N ₄并用TEM和SEM对吸波板进行了表征。研究表明，低含量的NGP和其他吸波填料可显着降低水泥浆的电阻率并提高其机械强度，并且在水泥水合产物中沉淀出致密的块状晶体。反射率测试表明，在2〜18 GHz频率范围内，三层水泥基吸波板的最小反射率达到-18.8 dB，小于-10 dB的最大带宽达到15.3 GHz。该研究可为新型三层水泥基吸波板的制备提供参考。